#! /bin/bash
read -p "please input number: " num
while true
do
	if [[ "$num" =~ ^[0-9]+$ ]] ;then
		break
	else
		read -p "不是数字，请重新输入数值: " num
	fi
done

read -p "please input prefix: " prefix
if [ -z "$prefix" ];then
	echo "error prefix"	
	exit
fi

for i in `seq $num`
do
	echo "$i"
done


